Sen. John McCain has informed Rep. David Schweikert that he will endorse Rep. Ben Quayle in their Member-versus-Member Republican primary in Arizona, according to a Schweikert source.

Schweikert did not seek McCain’s endorsement. Those in the Schweikert camp are under the impression that Arizona Sen. Jon Kyl (R) helped facilitate the endorsement. The Hotline first reported the news.

Rumblings about a McCain endorsement have been making the rounds in Arizona Republican circles for the past month or so.

Quayle already has Kyl's endorsement and former Secretary of State Condoleezza Rice endorsed him earlier this week.

A Quayle spokeswoman declined to comment.

The primary is on August 28. Roll Call rates the 6th district race as Safe Republican.